Dialysis apparatus

ABSTRACT

The invention is a dialysis apparatus for supplying dialysate at controlled concentration to an artificial kidney. The system provides for a supply of water at controlled temperature, and a supply of dialysate concentrate with means for mixing the controlled temperature water and concentrate to maintain a supply of dialysate at a controlled degree of concentration to be supplied to the artificial kidney. The system does not have a tank or reservoir of dialysate at a maintained degree of concentration. Interlocking safety controls are provided so as to discontinue the flow of dialysate in the event the temperature, the degree of concentration, or arterial pressure of the patient depart from predetermined limits. Additionally, audible and visual alarm signals are provided to indicate at all times when the said conditions are within limits and to indicate when any condition goes outside of the limits, the indication being both audible and visual. Further, the system provides means to mute the audible signal while still maintaining the machine in operation and further means are provided to safely sterilize the machine without danger to the patient.

United States Patent [72] Inventors Andrew Charles Edelson 10832Charuock Road, Los Angeles, 90034; Clyde Charles Nassau, 20602 PacificCoast Hwy., Malibu, Calif. 90265 [21] Appl. No. 784,830

[22] Filed Dec. 18, 1968 [45] Patented Feb. 16, 1971 [54] DIALYSISAPPARATUS 7 Claims, 3 Drawing Figs.

Primary ExaminerDalton L. Truluck: Attorney-Herzig and Walsh ABSTRACT:The invention is a dialysis apparatus for supplying dialysate atcontrolled concentration to an artificial kidney. The system providesfor a supply of water at controlled temperature, and a supply ofdialysate concentrate with means for mixing the controlled temperaturewater and concentrate to maintain a supply of dialysate at a controlleddegree of concentration to be supplied to the artificial kidney. Thesystem does not have a tank or reservoir of dialysate at a maintaineddegree of concentration. Interlocking safety controls are provided so asto discontinue the flow of dialysate in the event the temperature, thedegree of concentration, or arterial pressure of the patient depart frompredetermined limits. Additionally, audible and visual alarm signals areprovided to indicate at all times when the said conditions are withinlimits and to indicate when any condition goes outside of the limits,the indication being both audible and visual. Further, the systemprovides means to mute the audible signal while still maintaining themachine in operation and further means are provided to safely sterilizethe machine without danger to the patient.

Patepted Feb. 16,1911

2 Sheets-Sheet l DIALYSIS APPARATUS SUMMARY OF THE INVENTION Theinvention is an improved dialysis apparatus, or machine which is fullyautomatic and equipped with automatic interlocking safety controlswhereby to make possible operation of the machine by relativelyinexperienced personnel with complete safety to the patient.

Machines of this type are used to supply dialysate at predeterminedcontrolled concentration to artificial kidneys which are devices used totreat patients having kidney diseases. The dialysate under controlledconditions is passed through the artificial kidney and the patientsblood is pumped through the artificial kidney. The machine or system ofthe invention embodies certain improvements over machines of this typepreviously known in the art. in the machine of the invention thedialysate is supplied to the artificial kidney under automaticallycontrolled conditions as to temperature, degree of concentration, andarterial pressure of the patient. The construction and arrangement ofthe machine is such that it is not necessary to have a tank or reservoirof dialysate maintained at a controlled degree of concentration. Avessel of concentrate is maintained, the concentrate, of course, beingthe super saturated saline solution of water and the concentrate andthis solution may be maintained in the vessel simply by the addition ofprepackaged dried chemicals added to water. The control of flow fromthis vessel is by way of a manually adjustable needle valve to the endthat dialysate can be supplied at an appropriate degree of concentrationwhich is maintained within limits by way of a conductivity responsiveinstrument which is sensitive to the degree of concentration and is ableto discontinue the supply in the event that the concentration departsfrom said limits. The arrangement as stated, eliminates the need for astorage tank or reservoir of concentrate and maintenance of such a tankat a predetermined concentration. This makes possible the realization ofimportant advantages from the stand point of cost of the machine, costof dialysate, and by way of simplicity of construction, maintenance, andeffective control. Achievement of these results constitute primaryobjects of the invention.

The automatic controls responsive to the temperature of the dialysate,degree of concentration, and arterial pressure of the patient interlockto provide for complete safety of operation of the system even whenbeing operated by relatively inexperienced personnel, there beingaudible and visual alarm signals associated with each ofthecondition-responsive instruments to indicate when the conditions arewithin limits and when they are outside these limits. Furthermore, meansare provided in the system for muting the audible alarm signal whilestill being capable of having the machine operate to provide dialysate.Additionally, means are provided for sterilizing the machine after useunder conditions that are completely safe from the standpoint of thepatient. The realization of the safety factors as briefly referred toherein are among the additional and further objects of the invention.

Further objects and additional advantages of the invention will becomeapparent from the following detailed description and annexed drawingswherein:

FIG. I is a diagrammatic view of the components of the system whichsupply the dialysate solution to the artificial kidney.

FIG. 2 is a schematic electrical diagram of the electrical controls thatcontrol the supply of dialysate and provide for signal in the event ofoccurrence of any condition which would be unsafe, and also for signalsindicative of conditions being within safe limits.

FIG. 3 is a view of a modified form of system for supplying thedialysate solution.

Referring to FIG. 1 of the drawings numeral designates a pipe supplyinghot water, and numeral 12 designates a pipe supplying cold water. Thesepipes connect to a temperature responsive mixing valve 14. In the pipe10 is a pressure regulator 16-.which regulates the pressiire in pipe 10and in pipe 12 is a pressure regulator 18 which regulates the pressurein this pipe. The pressure regulators maybe of conventional type as maybe the valve 14 which is temperature responsive as indicated, beingconnected to an outlet pipe 24 in which the temperature is maintained bythe valve at a specific temperature which in this instance is preferably100 F.

The temperature of the mixed water is sensed and indicated by atemperature indicating instrument 28 connected by a line 30 to a sensingprobe 32 in the line 24. This temperature indicating instrument orthermometer may be of a conventional type.

Numeral 36 designates a flow controller in the line 24 depending uponthe setting of needle valve 38 in the line 24 beyond the controller 36.The fiow controller 36 may be of any of various types. It is shownschematically as being of a type embodying a plunger 40 movable inresponse to a diaphragm 42 in the casing of the controller 36. Thediaphragm chamber is connected to the line 24 beyond the needle valve 38by way of line 44, so that the diaphragm is responsive to pressurebeyond the needle valve. The controller 36 has a transverse channel 46in it and the plunger 40 is movable across this channelby the diaphragm42 to control the rate of fiow.

Beyond the needle valve 38 the line 24 connects to a flow meter 50 whichis an indicating type of instrument preferably placed on a control panelwhich indicates the rate of water flow.

The flow meter 50 is connected by line 52 to a filter pump 54 whichassists in mixing the dilutant with the concentrate. The filter pump isa known type of device which in the form of the invention is a venturiformed by nozzle 53 in the pump chamber which discharges toward or intothe orifice at the end of discharge line 55. Pump 54 serves to mix thewater and concentrate.

Numeral 60 designates a vessel in which a supply of concentrate isprovided which is the super saturated saline solution. Preferablyrecirculation is maintained at all times through this vessel by a pump62 which receives concentrate from the bottom vessel 60 through pipe 64and returns into the top of the vessel through a pipe 66.

Associated with the pump 62 is a chamber for concentrate which isconnected by pipe 70 to the filter pump 54, there being a needle valve72 in this line for adjusting the rate of flow of concentrate to thefilter pump 54. The filter pump 54 is connected to a tube coil or hosehaving loops in it as designated at 76 which in turn connects to thethree-way solenoid valve which is the dialysate valve 80. Thisconnection is through the electric cell 82 which isaconductivity-responsive cell that measures or senses the conductivityand hence the degree of concentration of the solution passing throughline 84 to the dialysate valve 80.

The dialysate valve is a solenoid operated three-way valve operated bythe electric solenoid 86. The solenoid valve allows dialysate to floweither through the line to the artificial kidney or through the line 92to drain 94.

In line 90 is a needle valve 95 and connected to it is negative pressuregauge 93. The artificial kidney is shown schematically at 91, the bloodflow in and out being indicated at 96 and 97. Dialysate drains from thekidney through line 98. By opening the negative pressure solenoid valve99 suction can be applied to the artificial kidney to augment the flowof dialysate. Numeral 100 designates a venturi device or pump havingnozzle 101 in chamber 105 which is connected to drain line 103. Coldwater line 106 connects to chamber 105 and in this line are the negativepressure valve 99, and pressure regulator 107. The degree of appliednegative pressure created by device 100 is controlled by needle valve95.

All of the parts of the system so far described are preferably of veryreliable types that are easy to maintain and are subject to veryeffective and precise automatic control with all of the necessary safetyfactors embodied in the control sequence. The automatic controls and thecontrol sequence will be described presently. it will be observed] thatno tank or reser voir of mixed dialysate at controlled concentration ispresent in the system so that it is not necessary to provide andmaintain such a tank. On the other hand the vessel 60 is merely providedin which the dry chemicals can be mixed, with the rate of flow ofconcentrate from the vessel 60 to the filter pump 54 being under thecontrol of the needle valve 72. Needle valve 72 is manually adjustableto provide a rate of flow of concentrate that mixes with the flow ofwater at controlled temperature to provide the flow of dialysate atappropriate concentration. The coil or loop 76 assists in the mixingwhich is at all times being monitored by the conductivity meter 82 tosimply operate the three-way valve 80 to cause the solution to flow todrain in the event that the degree of concentration deviates outside ofthe prescribed set limits.

As a modification of the system described, of course, the system may beoperated without employing the recirculation pump and a float valve maybe provided in the chamber at that point maintaining a fixed head ofliquid which then flows through the line 70 and the needle valve 72-tothe filter pump 54. Another alternative is that as shown in FIG. 3wherein the vessel 60' is connected through the needle valve 72 to thefilter pump 54. The vessel 60 is pressurized by way of air pressure froma pressure tank or cylinder 102 which provides for flow of pressurizedair through a line 102 and a pressure gauge 104 into the vessel 60 abovethe level of the concentrate. Thus, appropriate pressure is applied inthe vessel 60' to drive the concentrate through the line 70 to thefilter pump 54, and then as in the system as previously described theconductivity meter responds to the degree of concentration and controlsthe three-way valve.

FIG. 2 as indicated in the foregoing is a grid-type schematic diagram ofthe electrical controls and alarm circuitry. Preferably the power supplyis at 115 volts AC the line being designated by the numerals 110 and112. In the line is a fuse 114 and a manual control switch 116. Thesolenoid 86 for valve 80 appears adjacent to the contacts CR 111; TR101; and TR 111. The controls include the manual sterilizer switch 117,and the mute switch 118 which is manually actuatable. The controls alsoinclude the relays CR CR 11 and CR 12 which are designated by circlesand the various contacts of these relays are shown as either normallyopen or normally closed and designated by corresponding referencecharacters. The controls also include the relays TR 10; TR 11; TR 13 andTR 14 and the contacts at these relays which are either normally open ornormally closed are identified by corresponding reference characters. CRrelays are designated by circles and TR relays by rectangles. Thecharacter TR indicates that the relay is a time delay type havingtypically a time delay characteristic that may be from 10 seconds to 30seconds will elapse before the relay pulls in after being energized. Thecharacter CR indicates "control relay".

The controls also include the temperature control instrument 124; thearterial pressure control instrument 126; and the concentrate controlinstrument 128 which is a conductivity instrument. Numeral 130 is aconductivity indicating instrument which preferably is exposed on thecontrol panel of the machine.

Numeral 134 designates an audible signal device in the form of a buzzer.Numerals 136 through 150 designate red and green signal lights.

The operation of the system is very simple with the safety of thepatient a foremost factor at all times. The safety interlocks are soarranged that the machine cannot be used unless all vital monitoringgauges and alarm units are within their respective ranges.

The machine is started by closing the main switch 116. When this switchis closed supply of dialysate may begin unless an alarm or unsafecondition exists. The machine will not start until all of the unitsresponsive to temperature, conductivity, (Degree of concentration) andarterial pressure are indicating a safe condition and if not there willbe indicated an alarm condition by way of the alarm buzzer andrespective red signal lights as will be described.

As will be observed from FIG. 2 relay CR 11 is in series with thetemperature responsive instrument 124. The relay TR 11 is in series withthe arterial pressure responsive instrument 126. The relay TR 10 is inseries with the conductivity responsive instrument 128. As thetemperature, conductivity, and arterial pressure come within limitsthese relays will be deenergized and as this occurs the contacts CR 111,TR 101, and TR 111 in series with the dialysate solenoid 86 will closewhich is their normal position, and will cause the dialysate solenoid toopen the dialysate valve to permit flow of solution to the artificialkidney. After a 30 second time delay following closure of these contactsthe relay TR 14 will be energized this relay being a time delay relay.At the time that relay TR 14 is energized its contacts TR 141 will closeenergizing the negative pressure solenoid 129. When all of these eventshave taken place the machine is in condition to produce dialysate aslong as all of the alarm units stay within limits. The negative pressuresolenoid operates a valve making it possible to apply negative pressureacross the membranes of the artificial kidney, as described in theforegoing.

In the event an alarm condition exists the machine immediately stopsdialysis. This happens because opening of any of the contacts CR 111, TR101, or TR 111 will deenergize the solenoid 86 and the relay TR 14.Deenergization of relay TR 14 will deenergize the negative pressuresolenoid by opening contact TR 141. Energization of any of relays CR111; TR 10; or TR 11 will close one or more of contacts TR 112; TR 104;or CR 111 thus energizing buzzer 134 through closed contact CR 101.Energization'of any of these relays will cause its respective greensignal light to go off and its respective red warning light to come on.It will be observed that relay contacts TR 113; TR 114; TR 102; TR 103;CR112; CR 113 and CR 123 control green and red lights 136 through 150.

When an alarm condition exists it is desirable to mute the alarm buzzerand yet still keep the machine from continuing dialysis. This isaccomplished by way of the mute switch and circuitry. In order tosilence the buzzer the mute switch is depressed, that is, the switch118. When this occurs relay CR 10 will energize through closed contactTR 131. The relay CR 10 will stay energized until relay TR 13 energizes.This relay will energize after a 30-second time delay through contact CR103 the relay being a time delay type. After relay TR 13 is energized itwill deenergize relay CR 10 by opening contact TR 131. At this time ifthe out of limits condition has not been corrected the alarm buuer willagain sound, because contact CR 101 is again closed. The mute switchcircuitry will recycle at intervals resounding the buzzer until allconditions come back within limits.

After the machine has been used it is necessary to run a sterilizationsolution through it. In order to sterilize the machine without anypossibility of harming the patient the machine can be sterilized onlywhen the power switch is turned off. It is seen from the diagram of FIG.2 that when the power switch 116 is turned off relay CR 12 isdeenergized and only at this time can the sterilize switch 117 energizethe negative pressure solenoid. through contact CR 121. Thus, thenegative pressure valve 99 opens. Contact CR 122 of relay CR 12 willenergize solenoid 86 opening valve to allow flow to the artificialkidney. Any remaining dialysate is drained away and sterilizing solutionplaced in vessel 60. Alternatively, a canister containing sterilizingsolution is substituted for vessel 60 for performing the sterilizingfunction.

From the foregoing it will be observed that whenever an alarm unit goesout of limits its respective green light extinguishes and its redwarning light comes on, the alarm buzzer sounds and the machine stopsdialysis until the alarm condition is back within limits. The arterialpressure gauge and the pressure gauge have mechanical contacts thatcomplete the respective circuits when the needles or pointers on thegauges make contact with the high and low limit contacts and, thereforethese gauges are known as contact meters. The conductivity unit is acommercial device that is readily available on the market. When thearterial pressure gauge goes out of limits the relay energizes throughone of its contacts TR 115 deenergizes an external outlet 154 while itsother contact TR 116 energizes another external outlet, 156 whichoutlets can serve to control for example the patients blood pump, apressure cuff, etc.

From the foregoing, those skilled in the art will readily understand thenature of the invention, its construction and operation, and the mannerin which it achieves and realizes the objects and advantages as setforth in the foregoing.

The foregoing disclosure is representative of preferred forms of theinvention and is to be interpreted in an illustrative rather than alimiting sense the invention to be accorded the full scope of theappended claims;

I claim:

l. A dialysate supply and control system comprising:

a source of dialysate concentrate;

a mixing means;

first conduit means for conducting concentrate from said source to saidmixing means and means for maintaining concentrate delivered to saidconduit under controlled pressure;

selectively manual settable valve means in said first conduit betweensaid mixing means and said source of concentrate for establishingapredetermined rate of flow of concentrate therein;

a source of controlled temperature diluent and a second conduit meansfor conducting diluent from its source to said mixing means; s.

selectively settable means in said second conduit means for establishingand maintaining a predetermined rate of flow of diluent therein;

third conduit means for delivering mixed concentrate and diluent fromsaid mixing means to an artificial kidney or the like; and

, means in said third conduit means for detecting the concentration ofdialysate therein and responsive to deviation of said concentration froma predetermined range for stopping flow of said mixture to saidartificial kidney or the like. i

2. The system as in claim I, wherein the source of dialysate solutioncomprises a tank of concentrate and means for applying controlledpressure to the concentrate in the tank.

3. A system as in claim 1, including sources of hot and cold dilutantand a temperature responsive mixing valve for providing the controlledtemperature dilutant.

4. An apparatus as in claim 1 wherein said last-named means comprises avalve operable to stop the flow of dialysate to the artificial kidney.

5. An apparatus as in claim 4 including means responsive to temperatureand to arterial blood pressure of a patient for stopping flow ofdialysate.

6. An apparatus as in claim 1, including signal means operable toprovide a signal in the event of deviation of the degree ofconcentration of the dialysate from a predetermined value.

7. An apparatus as in claim 6 including manually operable means toterminate the signal and to cause the signal to be reinitiated after apredetermined time in the event the deviation remains present.

2. The system as in claim 1, wherein the source of dialysate solutioncomprises a tank of concentrate and means for applying controlledpressure to the concentrate in the tank.
 3. A system as in claim 1,including sources of hot and cold dilutant and a temperature responsivemixing valve for providing the controlled temperature dilutant.
 4. Anapparatus as in claim 1 wherein said last-named means comprises a valveoperable to stop the flow of dialysate to the artificial kidney.
 5. Anapparatus as in claim 4 including means responsive to temperature and toarterial blood pressure of a patient for stopping flow of dialysate. 6.An apparatus as in claim 1, including signal means operable to provide asignal in the event of deviation of the degree of concentration of thedialysate from a predetermined value.
 7. An apparatus as in claim 6including manually operable means to terminate the signal and to causethe signal to be reinitiated after a predetermined time in the event thedeviation remains present.